Stochastic resonance in ion channels characterized by information theory

We identify a unifying measure for stochastic resonance (SR) in voltage dep endent ion channels which comprises periodic (conventional), aperiodic, and nonstationary SR. Within a simplest setting, the gating dynamics is govern ed by two-state conductance fluctuations, which switch at random time point s between two values. The corresponding continuous time point process is an alyzed by virtue of information theory. In pursuing this goal we evaluate f or our dynamics the tau information, the mutual information, and the rate o f information gain. As a main result we find an analytical formula for the rate of information gain that solely involves the probability of the two ch annel states and their noise averaged rates. For small voltage signals it s implifies to a handy expression. Our findings are applied to study SR in a potassium channel. We find that SR occurs only when the closed state is pre dominantly dwelled upon. Upon increasing the probability for the open chann el state the application of an extra dose of noise monotonically deteriorat es the rate of information gain, i.e., no SR behavior occurs.